Basic Properties and Structural Characteristics of Phenyl Silicone
Phenyl silicone is a special type of silicone rubber, made by introducing phenylsiloxane segments (or methylphenylsiloxane segments) into the molecular chain. Its basic properties include:
Excellent low-temperature resistance: The glass transition temperature can be as low as -115°C, and it maintains flexible elasticity at -100°C.
High-temperature resistance: It can operate for long periods in high-temperature environments of 200-250°C.
Chemical corrosion resistance: It exhibits good resistance to acids, alkalis, and salts.
Structural Characteristics: The introduction of the phenyl group disrupts the regularity of the siloxane molecular structure and reduces the crystallinity of the polymer.

Corrosion Mechanism of Phenyl Silicone in Complex Chemical Environments
The corrosion behavior of phenyl silicone varies in different chemical environments:
Strong acid and alkali environments: Strong oxidizing acids such as concentrated nitric acid and hydrofluoric acid can break the silicon-oxygen (SiO) bonds, resulting in scission of the main chain. Medical dialysis machine seals exposed to undiluted nitric acid exhibited powdering within three months, and the intensity of the characteristic peak for silicon-oxygen bonds decreased by 47%.
Polar organic solvents: Methanol, acetone, and other solvents disrupt the cross-linked network through penetration. Automotive hydraulic system tests showed that silicone Y-rings exhibited a volume expansion of ≤3% after immersion in 10% sulfuric acid for 72 hours.
Aromatic hydrocarbons and chlorine-containing compounds: Benzene, carbon tetrachloride, and other compounds induce swelling or dissolution of surface substances. After immersion in a benzene-containing solvent for 100 hours, the compression set of automotive fuel pipe seals reached 45%.

Modification methods to improve chemical resistance
Surface treatment technologies
Surface roughening: Mechanical, chemical, or electrochemical methods are used to increase surface roughness and enhance adhesion.
Coating: Application of coatings such as silanes, titanates, and zirconium salts improves wear and corrosion resistance.
Surface plating: Plating with metals such as nickel, chromium, and tin significantly enhances corrosion resistance.
Plasma surface treatment: Microscopic cleaning, activation, or etching of surfaces using plasma.